|I think I found a bug with atstrings. I was trying to escape the @ with a backslash, and it gave me an error, and caused arc to behave strangely and hang until I ctrl-C'd and (tl)'d back.
arc> (declare 'atstrings t)
arc> (= x 1)
Error: "UNKNOWN::36: read: unknown escape sequence \\@ in string"
arc> 1 (this line was printed by arc, not me typing)
arc> Error: "reference to undefined identifier: _@x" (also printed by arc)
(arc hangs until i ctrl-C)|